"It's been a real problem," said Bill Wiebold, an MU plant sciences professor.

Farmers were set for a good yield because of summer weather, but corn stalks are rotting and falling over, Wiebold said, adding that wet conditions are lowering the quality and the price of crops.

Through Wednesday, the total October rainfall at Columbia Regional Airport was 9.63 inches — 6.78 inches above the average. Thursday's rainfall only added to the total. There's only been one wetter October in Columbia since 1890, and that was when 13.34 inches fell in 1941.

This October is also on pace to be the third coldest on record with an average temperature of 54.6 degrees. Only October 1917 (48.6 degrees) and October 1925 (47.2) have been colder.

Winds are bringing moisture from the Gulf of Mexico and slow-moving systems set the weather pattern this month, Kramper said.

Anthony Lupo, chairman of the MU atmospheric science department, said the jet stream has also been steering storms across the central U.S.